diff --git a/lib/Transforms/Vectorize/LoopVectorize.cpp b/lib/Transforms/Vectorize/LoopVectorize.cpp index cdd130f1354..475bea14850 100644 --- a/lib/Transforms/Vectorize/LoopVectorize.cpp +++ b/lib/Transforms/Vectorize/LoopVectorize.cpp @@ -106,8 +106,7 @@ struct LoopVectorize : public LoopPass { } DEBUG(dbgs() << "LV: Found a vectorizable loop ("<< VF << ") in "<< - L->getHeader()->getParent()->getParent()->getModuleIdentifier()<< - "\n"); + F->getParent()->getModuleIdentifier()<<"\n"); // If we decided that it is *legal* to vectorizer the loop then do it. InnerLoopVectorizer LB(L, SE, LI, DT, DL, VF); @@ -1849,6 +1848,15 @@ LoopVectorizationLegality::isInductionVariable(PHINode *Phi) { return NoInduction; } +bool LoopVectorizationLegality::isInductionVariable(const Value *V) { + Value *In0 = const_cast(V); + PHINode *PN = dyn_cast_or_null(In0); + if (!PN) + return false; + + return Inductions.count(PN); +} + bool LoopVectorizationLegality::blockNeedsPredication(BasicBlock *BB) { assert(TheLoop->contains(BB) && "Unknown block used"); @@ -2110,6 +2118,13 @@ LoopVectorizationCostModel::getInstructionCost(Instruction *I, unsigned VF) { case Instruction::Trunc: case Instruction::FPTrunc: case Instruction::BitCast: { + // We optimize the truncation of induction variable. + // The cost of these is the same as the scalar operation. + if (I->getOpcode() == Instruction::Trunc && + Legal->isInductionVariable(I->getOperand(0))) + return VTTI->getCastInstrCost(I->getOpcode(), I->getType(), + I->getOperand(0)->getType()); + Type *SrcVecTy = ToVectorTy(I->getOperand(0)->getType(), VF); return VTTI->getCastInstrCost(I->getOpcode(), VectorTy, SrcVecTy); } diff --git a/lib/Transforms/Vectorize/LoopVectorize.h b/lib/Transforms/Vectorize/LoopVectorize.h index e5a52596059..e5ef29052e2 100644 --- a/lib/Transforms/Vectorize/LoopVectorize.h +++ b/lib/Transforms/Vectorize/LoopVectorize.h @@ -320,6 +320,9 @@ public: /// Returns the induction variables found in the loop. InductionList *getInductionVars() { return &Inductions; } + /// Returns True if V is an induction variable in this loop. + bool isInductionVariable(const Value *V); + /// Return true if the block BB needs to be predicated in order for the loop /// to be vectorized. bool blockNeedsPredication(BasicBlock *BB); diff --git a/test/Transforms/LoopVectorize/X86/conversion-cost.ll b/test/Transforms/LoopVectorize/X86/conversion-cost.ll index 8f1bb545fa0..60c742e2205 100644 --- a/test/Transforms/LoopVectorize/X86/conversion-cost.ll +++ b/test/Transforms/LoopVectorize/X86/conversion-cost.ll @@ -4,7 +4,7 @@ target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f3 target triple = "x86_64-apple-macosx10.8.0" ;CHECK: @conversion_cost1 -;CHECK: store <2 x i8> +;CHECK: store <8 x i8> ;CHECK: ret define i32 @conversion_cost1(i32 %n, i8* nocapture %A, float* nocapture %B) nounwind uwtable ssp { %1 = icmp sgt i32 %n, 3